1. Technical Field
This disclosure generally relates to a solid cleaning medium that removes, without using water or solvent, dust and fine particles attached to an object used in an electrophotographic apparatus (such as a copier and a laser printer), such as toner particles attached to a component of a complex shape; and a dry-type cleaning apparatus using the solid cleaning medium; and particularly relates to solid cleaning medium and a thy-type cleaning apparatus that achieve higher cleaning efficiency by allowing continuous introduction of objects to be cleaned.
2. Description of the Related Art
Office equipment makers that manufacture copiers, facsimile machines, printers, and the like are actively engaged in recycling activities in which used products and component units are collected from users and then disassembled, cleaned, and assembled again for recycle use as components or as resin material in order to bring about a resource-recycling society. In order to recycle the components used in these products and component units, there is a need for a process that removes fine toner particles attached to the disassembled components and units for the cleaning purpose. The important issue is to reduce the cost and environmental impact associated with such cleaning.
In the case of a wet-type cleaning method that uses water or solvent to remove contaminants such as toner attached to components and units, the need for processing the waste fluid containing toner and energy consumption associated with a drying process after cleaning may lead to a cost increase in terms of environmental measures and energy conservation measures.
In the case of a dry-type cleaning method that uses air blowing forced air, the cleaning power is not high enough to remove highly adhesive toner, so that subsequent process steps are required such as manual wiping. Thus, cleaning is recognized as one of the bottleneck process steps in recycling and reusing the products. In the case of blast cleaning using dry ice, use of a large amount of dry ice may result in high running costs and a significant environmental impact.
As a solution to these problems, Patent Document 1 discloses a dry cleaning apparatus that discharges a charged object to be cleaned through stirring with an elastically deformable contact member in a rotating cylinder so as to lower the adhesion of dust attached to the object, and thus removes the dust from the object.
Patent Document 2 discloses a cleaning method using a dry cleaning medium. In this method, a developer (carrier) used in electrophotographic processes is used as a cleaning medium, and toner particles adhering to the object to be cleaned are removed by being attaching to the cleaning medium, thereby achieving dry cleaning.
Shot blasting techniques as disclosed in Patent Document 3 and Patent Document 4 are also used. The technique disclosed in Patent Document 3 is to remove extraneous substances from an object to be cleaned by blasting stainless microspheres or small stainless pieces onto the object. The technique disclosed in Patent Document 4 is to remove dirt from a resin container by causing granular solids to collide with the surface of a resin container with a high-speed air current.
Patent Document 5 discloses a dry cleaning apparatus. According to Patent Document 5, particulate cleaning media that attract particles are introduced into a vessel to be cleaned, and then a cleaning nozzle is inserted into an opening of the vessel. The cleaning nozzle provides a high-speed air current in the cleaning vessel to propel the cleaning media, which remove particles adhering to the inner surface of the cleaning vessel. The cleaning media collide with a mesh attached to an end of the cleaning nozzle, so that the mesh separates the particles adhering to the cleaning media by filtering and thus regenerates the cleaning media. The air blows up the regenerated median thereby cleaning the vessel repeatedly.
The apparatus of Patent Document 5 performs the process of blowing up the cleaning media and the process of regenerating the cleaning media by suction at the same time.
Further, Patent Documents 6 though 10 disclose blast cleaning techniques that use flexible cleaning media in order to prevent damage to or deformation of objects to be cleaned during cleaning.
Patent Document 11 discloses a cleaning method using thin cleaning media for higher cleaning efficiency.
Patent Document 1: Japanese Patent Registration No. 3288462
Patent Document 2: Japanese Patent Laid-Open Publication No. 2003-122123
Patent Document 3: Japanese Patent Registration No. 2889547
Patent Document 4: Japanese Patent Registration No. 3468995
Patent Document 5: Japanese Patent Laid-Open Publication No. 2005-329292
Patent Document 6: Japanese Patent Laid-Open Publication No. 2004-106100
Patent Document 7: Japanese Patent Laid-Open Publication No. 60-188123
Patent Document 8: Japanese Patent Laid-Open Publication No. 04-059087
Patent Document 9: Japanese Utility Model Registration No. 2515833
Patent Document 10: Japanese Patent Laid-Open Publication No. 07-088446
Patent Document 11: Japanese Patent Laid-Open Publication No. 2007-29945
In the dry cleaning apparatus of Patent Document 1, the impact power of the contact member on the object due to stirring is not high enough to remove highly adhesive dust.
The dry cleaning apparatus of Patent Document 2 needs to improve the cleanliness of the cleaning medium in order to improve the cleaning quality. The centrifugal separation effect of air circulation (cyclone method) is not sufficient for this purpose in terms of separation power. Further, in order to improve cleaning quality, there is a need to replace the cleaning media again and again after the cleaning media attract and hold toner, resulting in cleaning inefficiency and the need for a large amount of cleaning media.
The dry cleaning apparatuses of Patent Document 3 and 4 use metal microspheres, small metal pieces, or granular solids as cleaning media, which scrape and roughen the surface of the objects to be cleaned while removing dirt from the objects, and therefore cannot be used in the case damage to the objects to be cleaned is not allowed.
The dry cleaning apparatus of Patent Document 5 that performs the process of blowing up the cleaning media and the process of regenerating the cleaning media by suction at the same time is effective for cleaning a small vessel. However, in the case of cleaning in a large cleaning tank such as one in which the cleaning media are introduced and moved, the cleaning media do not fly around but stay in the same place because of dispersed energy of flying the cleaning media. Thus the performance of flying and regenerating the cleaning media is lowered, which results in a lower cleaning performance.
The dry cleaning apparatuses of Patent Documents 6 through 10 require long time for cleaning, and have difficulty in removing highly adhesive particles.
In the dry cleaning apparatus of Patent Document 11, the cleaning media adhere to the wall of the cleaning tank, so that the amount of cleaning media available for cleaning is reduced, which results in lower cleaning efficiency. Further, in the step of removing cleaning media from the object after the cleaning process, the cleaning media adhering to the object increase the time required for removal of the cleaning media. Moreover, the cleaning media are often stuck in joints and seams in the object or in joints and seams in the cleaning tank, which also increases the time required for removal of the cleaning media.